I have a scenario where I have a server component/module and I have several clients which are using server for various functionalities. These clients can be a windows application, WPF application, smart device application or web application.
I want to create a validation service on server side for example when a client make a request with something, the validation service on server side should validate the request and should provide feedback to the client after validation.
Client can make many type of request lets say
SaveProduct(Product product) or
SaveEmployee(Employee employee) etc.
How should I design this kind of scenario, which design pattern should I use?